The Arizona Diamondbacks have undoubtedly been the busiest team so far this off-season. They handed out the biggest free agent contract to Zack Greinke at six years, $206.5 million. $34.42M a season shattered baseball’s previous mark (Miguel Cabrera; $31M). But Arizona was hardly finished.

Finally adding to the core one of baseball most underrated players and underrated superstars, A.J. Pollock and Paul Goldschmidt, the D-Backs had an ace. They wanted another one, or at least a number two depending on how you view…

The Atlanta Braves are in a rebuild as deep as the 1985 Draft Class. Acquired along with former shiny prospect Tyrell Jenkins last November for impending free agent Jason Heyward and reliever Jordan Walden, Shelby Miller finally broke out with his change of scenery.

At age 24, Miller posted a 3.02 ERA with a 171:73 K:BB ratio in 205.1 innings, earning a spot on the National League All-Star Team.

A pitcher at 24 is, has been and will always be young, but the Braves aren’t set on contending for several more years and figured to gauge the value on Miller this off-season. The righty is also arbitration eligible for the first time next off-season. Apparently, they were aiming quite high, asking the Chicago Cubs for NL Rookie of the Year Kris Bryant in any deal for Miller (Chicago Sun-Times).

The market has changed in both free agency (see: David Price contract) as well as the trade market, and the Braves were only going to deal Miller for a crazy package.

Miller’s résumé—former 1st round pick in 2009, MLB.Com’s 5th ranked prospect in 2011, successful seasons with St. Louis at ages 22 and 23 and his breakout campaign last year—spoke for itself. If you’re going to trade a guy like that, you’re going to ask for the moon. I don’t think anybody expected them to receive said moon, but they did.

The Arizona Diamondbacks traded a massive haul to acquire Shelby Miller and Minor League pitcher Gabe Speier. They dealt the top pick of last June’s MLB Draft, shortstop Dansby Swanson, top pitching prospect Aaron Blair and everyday outfielder Ender Inciarte to acquire the services of Miller. Wow, indeed.

It still shocks me as I type it and say it over and over in my head. Swanson is the first number one overall pick to be traded since 2003 when the Florida Marlins traded the first pick from 2000 Adrian Gonzalez to the Texas Rangers for reliever Ugeth Urbina. Gonzalez was coming off three so-so and injury-plagued years in the Marlins system. Swanson is as fresh as it gets coming off being the top selection and the supposed new face of the Arizona Diamondbacks franchise.

I guess (with a capital G!) it’s worth noting that after making this move the Marlins won the World Series.

Major League Baseball’s new rule about Players to Be Named Later, inspired by the leak of Trea Turner‘s involvement in the Padres-Nationals-Rays trade last Winter, allows for Swanson to join the Braves immediately instead of waiting until a year from his draft date.

So how good can Dansby Swanson be? Well, the idea behind drafting a player with the top pick is thinking he’s going to be a superstar. Duh. To see Arizona let Swanson go at any time in his career would have been noteworthy, but half a year to the day from him putting on the D-Backs cap in Secaucus, New Jersey was/is truly incredible.

After playing three years at Vanderbilt (including a 2014 College World Series Championship and a second place 2015 finish) Swanson is already 21 and will likely see Double-A sooner rather than later. He spent 22 games with short-season Single-A ball, slashing .289/.394/.482 along with an even 14:14 K:BB ratio plus seven doubles, three triples, a home run and 11 RBI. Safe to say his already topflight stock only went up. MLB.com already has him ranked 10th in their Top 100 Prospects.

Another player being sent to Atlanta who caught some eyes is the 6 foot 5 starting pitcher, Aaron Blair. Blair was drafted 36th overall in 2013 and entered last season as a top 50 prospect in baseball according to Baseball America and Baseball Prospectus. Last season he delivered on such rave scouting reports.

He made the jump to AA in 2014 and only improved in 2015 with an effortless jump to the next level. Across Double-A and Triple-A, he posted a 2.92 ERA in 25 starts/160.1 IP. After striking out 171 in 2014, that number came down to a still very good 120 in 2015 and walks were once again held to 51.

Blair, who turns 24 next May, has a very good chance to pitch in the Major Leagues next season. In Atlanta’s bloated farm system, he competes with many arms for the top spot there, while Dansby Swanson is undoubtedly the club’s new top prospect.

The other arms in the Braves farm are all ones that came from trades or the same draft as Swanson. Kolby Allard was drafted 14th overall, Touki Toussaint was acquired in trade, also from Arizona, and also in a very, very peculiar deal for just Phil Gosslein and the salary relief of Bronson Arroyo. Also in the mix and perhaps the only superior prospect to Blair is Sean Newcomb, acquired for Andrelton Simmons just weeks ago. The Braves are indeed busy, and stockpiling to no foreseeable end.

Also headed to Atlanta is outfielder Ender Inciarte. Signed out of Venezuela in 2008, Inciarte progressed through Arizona’s system as a great speed-arm combo, but surprised at the Major League level with the bat. He finished 5th in Rookie of the Year voting in 2014 and in 2015 took his game to the next level, entrenching him in the Diamondbacks future plans…or so we thought. He hit .303, tied for 15th in the league and added 21 steals.

Along with Miller, Arizona also receives Minor League pitcher Gabe Speier. Originally a 19th round pick in 2013 by the Red Sox, Speier has simply been a trade name to this point. He’s been dealt three times in 12 months (and twice in two months), from Boston to Detroit to Atlanta to now Arizona.

When you are traded, somebody values you. Speier, 20, had a 2.86 ERA over 44 innings with a 3:1 (actual 36:12) K:BB ratio in Low-A for the Tigers. MLB.com does not slot him into their top 30 Diamondbacks prospects, but obviously he’s the last piece in this deal with upside to be desired.